DOCSLIB.ORG

How to Calculate the Load Pole and ESR Zero When Using Hybrid Output Capacitors

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
How to Calculate the Load Pole and ESR Zero When Using Hybrid Output Capacitors Application Report SLVAE26A–September 2018–Revised April 2019 How to Calculate the Load Pole and ESR Zero When Using Hybrid Output Capacitors Hao Zhang, Jason Wang ABSTRACT Multi-layer ceramic (MLCC), aluminum electrolytic, tantalum, and polymer are the capacitor types most widely used in DC/DC switching regulator circuits. In practical applications, a power designer can use a hybrid capacitor network, formed by combining different capacitor types, in an effort to achieve low ESR and high capacitance. This can be a very effective method of reducing output ripple and improving load transient performance. This application report provides a method to analyze how the hybrid capacitor network affects the loop. The Section 1 section introduces the key characteristics of each of the different types of capacitors. The Section 2 section discusses peak current mode power stage small signal modeling with a hybrid output capacitor network. Finally, the Section 3 section verifies the analysis with bench test results on TPS65400EVM. Contents 1 Introduction ................................................................................................................... 2 2 Current Mode Power Stage Small Signal Modeling..................................................................... 3 3 Bench Verification ........................................................................................................... 7 4 Summary .................................................................................................................... 12 5 References .................................................................................................................. 12 List of Figures 1 Simplified Current Mode Functional Block Diagram .................................................................... 3 2 Current Mode Buck Converter Circuit With Hybrid Output Capacitor Network ...................................... 4 3 Simplified Power Stage Bode Plot of Single Output Capacitor Configuration ....................................... 6 4 Simplified Power Stage Bode Plot of Hybrid Output Capacitor Network Configuration ............................ 7 5 Simplified Schematic of All MLCC Output Capacitor Configuration................................................... 8 6 Bode Plot of All MLCC Output Capacitor Configuration (VOUT = 3.3 V, IOUT = 1.5 A)................................ 8 7 Simplified Schematic of Hybrid Output Capacitor Configuration ...................................................... 9 8 Bode Plot of Hybrid Output Capacitor Configuration .................................................................. 10 9 Simplified Schematic of Single Polymer Output Capacitor Configuration .......................................... 10 10 Bode Plot of Single Polymer Output Capacitor Configuration (VOUT = 3.3 V, IOUT = 1.5 A) ....................... 11 11 Gain Frequency Response Comparison Among Hybrid, MLCC, and Polymer Output Capacitor Configuration ............................................................................................................... 11 List of Tables 1 Comparison of Different Types of Capacitors............................................................................ 2 2 Basic Configurations of TPS65400EVM .................................................................................. 7 3 Parameters of Capacitors Used in Output Capacitor Network......................................................... 9 Trademarks All trademarks are the property of their respective owners. SLVAE26A–September 2018–Revised April 2019 How to Calculate the Load Pole and ESR Zero When Using Hybrid Output 1 Submit Documentation Feedback Capacitors Copyright © 2018–2019, Texas Instruments Incorporated Introduction www.ti.com 1 Introduction Output capacitors are critical components for a switch-mode power supply. To select output capacitors for a DC/DC switching regulator application, the basic parameters you must pay attention to include capacitance, equivalent series resistance (ESR), rated voltage, and size. Table 1 compares the four types of capacitors. Table 1. Comparison of Different Types of Capacitors CAPACITANCE ESR RATED VOLTAGE SIZE Multi-layer Ceramic Low Low Medium Small Capacitor Aluminum Electrolytic High High Various Large Capacitor Tantalum Capacitor Medium Medium Medium Medium Polymer Capacitor High Medium Medium Medium Generally speaking, MLCC provides very low ESR, which is critical to compress the resistive output ripple. Aluminum electrolytic capacitors provide a large amount of capacitance, but have the highest ESR among the four capacitor types. Tantalum and polymer capacitors have medium-range capacitance values, ESR, and rated voltage. By using a hybrid capacitor network, designers can take advantage of the benefits of each capacitor type. In applications where small ripple, overshoot, and undershoot are required, hybrid output capacitor networks are very common. Loop stability is another important topic for DC/DC switching regulator circuit design. In DC/DC converter small signal modeling, the capacitance and ESR values of the output capacitor have a direct effect on the poles and zeros in the open loop transfer function. With the presence of a hybrid output capacitor network, new poles and zeros are introduced into the loop by the network itself. This application report discusses how hybrid output capacitors influence the loop, and then verifies the analysis using the TPS65400EVM. 2 How to Calculate the Load Pole and ESR Zero When Using Hybrid Output SLVAE26A–September 2018–Revised April 2019 Capacitors Submit Documentation Feedback Copyright © 2018–2019, Texas Instruments Incorporated www.ti.com Current Mode Power Stage Small Signal Modeling 2 Current Mode Power Stage Small Signal Modeling Figure 1 shows the simplified functional block diagram of a peak current mode DC/DC circuit. Current + Sense ± VIN Power stage dÖ vÖ Control out L Logic ESR Rload RFBT COUT vÖFB RFBB ± vÖ COMP Compensation EA + Network VREF Control stage Figure 1. Simplified Current Mode Functional Block Diagram To analyze and judge the loop stability by open loop transfer function and Bode plot, the loop is split into two components: Gopen )s( Gdv H)s( vd )s( where • Gdv(s) are the transfer function from control to the output ( to ), including the PWM modulator and power stage. Ö Ö • Hvd(s) is the transfer function from the output to control ( vout to d ), including the feedback path, compensation network. (1) Poles and zeros in power stage have a direct effect on the loop transfer function. To understand how the hybrid output capacitor network affects the loop, calculate the poles and zeros in the power stage. The calculation can vary in the different control mode, as they have different control to output transfer function Gdv(s). This application report shows how to do the calculation based on a current mode DC/DC converter circuit. Impedance of hybrid output capacitor network is discussed first. Based on that, the effect of the network on current mode DC/DC circuit is analyzed. SLVAE26A–September 2018–Revised April 2019 How to Calculate the Load Pole and ESR Zero When Using Hybrid Output 3 Submit Documentation Feedback Capacitors Copyright © 2018–2019, Texas Instruments Incorporated Current Mode Power Stage Small Signal Modeling www.ti.com 2.1 Impedance of Hybrid Output Capacitor Network Figure 1 shows that the output capacitor in the functional block diagram is simplified as a single capacitor. Impedance of a single capacitor with a specific ESR is: 1+ s ESR C Zcap )s( sC (2) When the output capacitor is substituted by an output capacitor network, the situation can be different. Figure 2 shows two capacitors with same or different capacitance and ESR that are put in parallel. + Current ± Sense VIN Hybrid Output Capacitor Netwrok Vout Control Logic L ESR1 ESR2 RFBT Rload Cout1 Cout2 RFBB GND ± Compensation EA + Network VREF Figure 2. Current Mode Buck Converter Circuit With Hybrid Output Capacitor Network Impedance of the hybrid capacitor network Zcap(s) can be expressed as: 1 1 Zcap )s( (R1 + ) //(R2 + ) sC1 sC 2 where • R1 is the ESR of C1 • R2 is the ESR of C2 (3) If you expand Equation 3, you have: 1( + sR C ) (1+ sR C ) Z )s( 1 1 2 2 cap ª º C1C 2 s(C1 + C 2 ) …1+ s (R1 + R 2 ) » C + C ¼ 1 2 (4) Equation 4 indicates when the capacitance and ESR are different. There is an initial pole, a parallel pole, and two ESR zeros in the impedance expression. A specific situation is where the two capacitors are same, C1 = C2 = C, R1 = R2 = R. Equation 4 can be further simplified as: 4 How to Calculate the Load Pole and ESR Zero When Using Hybrid Output SLVAE26A–September 2018–Revised April 2019 Capacitors Submit Documentation Feedback Copyright © 2018–2019, Texas Instruments Incorporated www.ti.com Current Mode Power Stage Small Signal Modeling 1+ sRC Zcap )s( C2s (5) In this situation, two of the same output capacitors can be equalized to one single capacitor with two times capacitance and half ESR. 2.2 Pole and Zero Calculation in Current Mode Power Stage The distribution of poles and zeros in the loop transfer function depends on both power stage characteristic and control mode. As discussed in the Current-Mode Modeling for Peak, Valley and Emulated Control Methods Application Report, the transfer function of peak current mode buck converter power stage is: s 1 + Ö w v out 1 ESR Ö R 1 s s v c i + 1( + 1() + ) w w R o K m 0 L where • Ro is the loading resistance VIN K m V • Km is the modulator voltage gain, which is
Load more

Recommended publications
  • Introduction What Is a Polymer Capacitor?
    ECAS series (polymer-type aluminum electrolytic capacitor) No. C2T2CPS-063 Introduction If you take a look at the main board of an electronic device such as a personal computer, you’re likely to see some of the six types of capacitors shown below (Fig. 1). Common types of capacitors include tantalum electrolytic capacitors (MnO2 type and polymer type), aluminum electrolytic capacitors (electrolyte can type, polymer can type, and chip type), and MLCC. Figure 1. Main Types of Capacitors What Is a Polymer Capacitor? There are many other types of capacitors, such as film capacitors and niobium capacitors, but here we will describe polymer capacitors, a type of capacitor produced by Murata among others. In both tantalum electrolytic capacitors and aluminum electrolytic capacitors, a polymer capacitor is a type of electrolytic capacitor in which a conductive polymer is used as the cathode. In a polymer-type aluminum electrolytic capacitor, the anode is made of aluminum foil and the cathode is made of a conductive polymer. In a polymer-type tantalum electrolytic capacitor, the anode is made of the metal tantalum and the cathode is made of a conductive polymer. Figure 2 shows an example of this structure. Figure 2. Example of Structure of Conductive Polymer Aluminum Capacitor In conventional electrolytic capacitors, an electrolyte (electrolytic solution) or manganese dioxide (MnO2) was used as the cathode. Using a conductive polymer instead provides many advantages, making it possible to achieve a lower equivalent series resistance (ESR), more stable thermal characteristics, improved safety, and longer service life. As can be seen in Fig. 1, polymer capacitors have lower ESR than conventional electrolytic Copyright © muRata Manufacturing Co., Ltd.
    [Show full text]
  • Review of Technologies and Materials Used in High-Voltage Film Capacitors
    polymers Review Review of Technologies and Materials Used in High-Voltage Film Capacitors Olatoundji Georges Gnonhoue 1,*, Amanda Velazquez-Salazar 1 , Éric David 1 and Ioana Preda 2 1 Department of Mechanical Engineering, École de technologie supérieure, Montreal, QC H3C 1K3, Canada; [email protected] (A.V.-S.); [email protected] (É.D.) 2 Energy Institute—HEIA Fribourg, University of Applied Sciences of Western Switzerland, 3960 Sierre, Switzerland; [email protected] * Correspondence: [email protected] Abstract: High-voltage capacitors are key components for circuit breakers and monitoring and protection devices, and are important elements used to improve the efficiency and reliability of the grid. Different technologies are used in high-voltage capacitor manufacturing process, and at all stages of this process polymeric films must be used, along with an encapsulating material, which can be either liquid, solid or gaseous. These materials play major roles in the lifespan and reliability of components. In this paper, we present a review of the different technologies used to manufacture high-voltage capacitors, as well as the different materials used in fabricating high-voltage film capacitors, with a view to establishing a bibliographic database that will allow a comparison of the different technologies Keywords: high-voltage capacitors; resin; dielectric film Citation: Gnonhoue, O.G.; Velazquez-Salazar, A.; David, É.; Preda, I. Review of Technologies and 1. Introduction Materials Used in High-Voltage Film High-voltage films capacitors are important components for networks and various Capacitors. Polymers 2021, 13, 766. electrical devices. They are used to transport and distribute high-voltage electrical energy https://doi.org/10.3390/ either for voltage distribution, coupling or capacitive voltage dividers; in electrical sub- polym13050766 stations, circuit breakers, monitoring and protection devices; as well as to improve grid efficiency and reliability.
    [Show full text]
  • Understanding Polymer and Hybrid Capacitors Advanced Capacitors Based on Conductive Polymers Maximize Performance and Reliability
    WHITE PAPER Understanding Polymer and Hybrid Capacitors Advanced capacitors based on conductive polymers maximize performance and reliability The various polymer and hybrid capacitors have distinct sweet spots in terms of their ideal voltages, frequency characteristics, environmental conditions and other application requirements. In this paper, we’ll show you how to identify the best uses for each type of advanced capacitor. We’ll also highlight specific applications in which a polymer or hybrid capacitor will outperform traditional electrolytic or even ceramic capacitors. POLYMER CAPACITOR VARIETIES Polymer capacitors come in four main varieties, including the hybrid. Each type has different electrolytic and electrode Hybrid capacitor technology combines the performance benefits of materials, packaging and application targets: electrolytic and polymer capacitors. • Layered polymer aluminum capacitors use conductive Capacitors may seem simple enough, but specifying them has polymer as the electrolyte and have an aluminum cathode actually grown more complex in recent years. The reason why (see Figure 1). Depending on the specific model, these comes down to freedom of choice. The universe of capacitors capacitors cover a voltage range from 2-25V and offer has expanded greatly over the past few years, in large part capacitances between 2.2-560µF. The distinguishing because of capacitor designs that take advantage of advances electrical characteristic of these polymer capacitors is in conductive polymers. their extremely low equivalent series resistance (ESR). For example, some of our SP-Cap™ polymer capacitors have These advanced capacitors sometimes use conductive polymers ESR values as low as 3mΩ, which is among the lowest in to form the entire electrolyte. Or the conductive polymers can be used in conjunction with a liquid electrolyte in a design known as a hybrid capacitor.
    [Show full text]
  • Solid Polymer Aluminum SMT Capacitors Tape Specifications Reel Specifications
    Application Guide, Solid Polymer Aluminum SMT Capacitors Tape Specifications Reel Specifications SPA ESRD ESRE ESRH SPA Type t2 = H + 0.3 mm ±0.2 mm W D– P A B EF P 1 P t ±0.3 + 0.1/–0.0 Ø ±0.2 2 ±0.2 ±0.2 1 A ±0.2 B Min. C ±0.5 D ±0.8 E ±0.5 W ±1.0 t 12.0 1.8 5.5 1.5 4.0 8.0 2.0 7.7 4.6 0.4 333.0 50.0 13.0 21.0 2.0 14.0 3.0 Tol.: ± mm unless otherwise specified Design Kits Design kits containing various ratings are available through the CDE web site. Typical Temperature Characteristics Capacitance Change at 120 Hz Dissipation Factor at 120 Hz 20 10 10µF/6.3V 10µF/6.3V 8 10 6 % ) 0 C ( DF ( % ) ǻ 4 -10 2 -20 0 -60 -20 20 60 100 -60 -20 20 60 100 Temperature (°C) Temperature (°C) CDE Cornell Dubilier • 1605 E. Rodney French Blvd. • New Bedford, MA 02744 • Phone: (508)996-8561 • Fax: (508)996-3830 • www.cde.com Application Guide, Solid Polymer Aluminum SMT Capacitors Typical Impedance and Equivalent Series Resistance ESRD (3.1 mm Ht.) 100.000 ESRD680M08R 68 uF/8 V Impedance/E.S.R. 10.000 ESRD121M04R 120 uF/4 V Impedance/E.S.R. 1.000 ESRD181M02R Ohms 180 uF/2 V Impedance/E.S.R. 0.100 0.010 0.001 0.1 1 10 100 1000 10000 100000 Frequency (kHz) ESRE 100.000 ESRE101M08R 100 uF/8 Vdc 10.000 Impedance/E.S.R.
    [Show full text]
  • Polymer Tantalum Capacitors with Suppressed Transient Current
    POLYMER TANTALUM CAPACITORS WITH SUPPRESSED TRANSIENT CURRENT Jan Petržílek Miloslav Uher Jiří Navrátil R&D Manager of AVX Senior Development Senior Development Tantalum Division Engineer Engineer WWW.AVX.COM TABLE OF CONTENTS 01 INTRODUCTION TRANSIENT CURRENTS (ANOMALOUS CURRENTS) 01 DESCRIPTION OF THE PHENOMENON - DC Leakage Measurement ...................................................01 - Anomalous Charging Currents .............................................03 - Surge Current Anomalies .....................................................04 RESULTS OF THE NEW TECHNOLOGY OF POLYMER 06 CAPACITORS WITH NO CURRENT ANOMALY 07 CONCLUSION 09 REFERENCES 09 AUTHORS POLYMER TANTALUM CAPACITORS WITH SUPPRESSED TRANSIENT CURRENT INTRODUCTION Tantalum electrolytic capacitors are renowned for their high capacitance and volumetric efficiency, parametric stability over a long service lifetime, and long-term reliability under harsh operating conditions. The anode is constructed of a porous pellet of sintered tantalum powder with a dielectric of tantalum pentoxide formed by electrochemical anodization. The traditional cathode materials have been either a liquid electrolyte (wet hermetic types) or manganese dioxide (solid MnO2 surface mount types). However, the most recent material, fast becoming a popular option, is conductive polymer. The Polymer Tantalum capacitor was originally marketed toward consumer electronic applications, however after years of effort and continuous improvement, significant technological breakthroughs now permit use in many
    [Show full text]
  • Boosting Performance of Electrolytic Capacitors with Conductive Polymer Dispersions
    Next Generation of Polymer Capacitors: Boosting Performance of Electrolytic Capacitors with Conductive Polymer Dispersions Udo Merker1, Klaus Wussow1, Katrin Asteman1, Wise Chow2, Willie Luo2, Zhenquan Chen2 1Heraeus Deutschland GmbH & Co KG, Chempark Leverkusen, 51368 Leverkusen, Germany, [email protected] 2Zhaoqing Beryl Electronic Technology Co., Ltd., No.8 Duanzhou Road, Zhaoqing City, Guangdong Province, P.R. CHINA, [email protected] Abstract The major use of polymer aluminum and tantalum capacitors is for low voltage consumer electronics. The development of conductive polymer dispersions has extended the voltage range of polymer capacitors up to 125 V in the last years and opened the door for high reliability applications like automotive. We present the next generation of polymer aluminum capacitors reaching rated voltage of 400 V. Life-test, frequency and low temperature characteristics are reported. Introduction For more than 20 years, applications of polymer aluminum and tantalum capacitors have been driven by low ESR requirements [1]. Traditional electrolytic capacitors were not able to meet these requirements of modern electronic circuits like motherboards. However, the application field of polymer capacitors was limited to consumer electronics mainly due to the lack of high voltage capability, relatively high DC leakage current (DCL) and low reliability performance. During the last decade, these restrictions of polymer capacitors have been overcome and high voltage, low DCL and high reliability applications could be accessed. The rated voltage range of polymer capacitors has been extended from maximum of about 25 V to 125 V [2]. In combination with a superior DCL performance, the new polymer capacitors have been introduced in high reliability applications like automotive.
    [Show full text]
  • Dielectric Properties of Multilayer Polymer Films
    DIELECTRIC PROPERTIES OF MULTILAYER POLYMER FILMS FOR HIGH ENERGY DENSITY CAPACITORS & PREDICTING LONG-TERM CREEP FAILURE OF A BIMODAL POLYETHYLENE PIPE FROM SHORT-TERM FATIGUE TESTS by Zheng Zhou Submitted in partial fulfillment of the requirements For the degree of Doctor of Philosophy Dissertation Advisors: Prof. Eric Baer and Prof. Anne Hiltner Department of Macromolecular Science and Engineering CASE WESTERN RESERVE UNIVERSITY August, 2013 CASE WESTERN RESERVE UNIVERSITY SCHOOL OF GRADUATE STUDIES We hereby approve the thesis/dissertation of Zheng Zhou candidate for the Ph.D. degree *. (signed) Prof. Eric Baer (chair of the committee) Prof. Lei Zhu Prof. Donald Schuele Prof. Alex Jamieson (date) May 8, 2013 *We also certify that written approval has been obtained for any proprietary material contained therein. Copyright © 2013 by Zheng Zhou All rights reserved Dedication To my wife, Ying Chen, and my parents, Baihua, and Jieshui TABLE OF CONTENTS LIST OF TABLES iii LIST OF FIGURES iv ACKNOWLEDGEMENTS xi ABSTRACT xiii PART A 1 CHAPTER 1 2 INTERPHASE/INTERFACE MODIFICATION ON THE DIELECTRIC PROPERTIES OF PC/P(VDF-HFP) MULTILAYER FILMS FOR HIGH ENERGY DENSITY CAPACITORS CHAPTER 2 51 MULTILAYERED POLYCARBONATE/POLY(VINYLIDENE FLUORIDE-CO-HEXAFLUOROPROPYLENE) FOR HIGH ENERGY DENSITY CAPACITORS WITH ENHANCED LIFETIME CHAPTER 3 92 FRACTURE PHENOMENA IN MICRO- AND NANO-LAYERED POLYCARBONATE/POLY(VINYLIDENE FLUORIDE-CO- HEXAFLUOROPROPYLENE) FILMS UNDER ELECTRIC FIELD FOR HIGH ENERGY DENSITY CAPACITORS i PART B 131 CHAPTER 4 132 PREDICTING LONG-TERM CREEP FAILURE OF BIMODAL POLYETHYLENE PIPE FROM SHORT TERM FATIGUE TESTS BIBLIOGRAPHY 167 ii LIST OF TABLES CHAPTER 1 1.1 PC/tie/P(VDF-HFP) multilayer films under investigation 31 1.2 Maximum discharge energy density and hysteresis property values 44 at 500 kV/mm as a function of nominal tie layer thickness for the 65-layer 46/8/46 PC/tie/P(VDF-HFP) multilayer films.
    [Show full text]
  • Conductive Polymer Aluminum Solid Electrolytic Capacitors "PZ-CAP" Introduction
    Conductive Polymer Aluminum Solid Electrolytic Capacitors "PZ-CAP" Introduction Under the concern on depletion of global resources due to global warming, radical growth of developing countries and population increase in cities and developing countries, effective utilization of energy is becoming to the common subject, for which many countries have started projects for smart grid, smart city and smart community. In electric and electronic field, development of products contributing to global warming and reduction of CO 2 emission is now popular. In such circumstances, the market is demanding downsizing and higher performance of electronic devices including aluminum electrolytic capacitor, which is the main product of Rubycon. Conductive polymer aluminum solid electrolytic capacitor (“Solid Electrolytic Capacitor”) has the advantages such as wide operation temperature range, compact, low ESR and high resistance against ripple current, but the only disadvantage is low working voltage under 35V. Then the applications of the capacitor have been restricted as a component of 25V or lower. Rubycon has brought PZ-CAP (Photo-1) to the market realizing high withstand voltage with the original technologies, while many capacitor manufacturers have been developing Solid Electrolytic Capacitor at high operation voltage. PZ-CAP Series is described in this paper. Specifications （Photo-1）Winding type Conductive Polymer Aluminum Solid Electrolytic Capacitors “PZA Series” / “PAV Series” Standard Size Need of High Working Voltage for Solid Electrolytic Capacitor Conventional aluminum non-solid electrolytic capacitor (“Al Electrolytic Capacitor”) uses liquid electrolyte to work through ion conduction as transfer of electric charges. On the other hand, Solid Electrolytic Capacitor uses electron conduction for such transfer, so that conductivity is 4 or 5 digits higher than that for Al Electrolytic Capacitor, which means superior ESR.
    [Show full text]
  • Polymer Aluminum Electrolytic Capacitors
    CONDUCTIVE POLYMER ALUMINUM ELECTROLYTIC CAPACITORS Hi-CAP (Conductive Polymer Aluminum Electrolytic Capacitor) Hi-CAP is an electrolytic capacitor that uses a highly electric conductive polymer as it’s electrolyte. Hi-CAP has excellent temperature and load life characteristics due to adoption of stable polymer in high temperature. Compared to other electrolytic capacitors, the Hi-CAP is a low impedance capacitor suitable for high frequency making it ideal for digital circuit. 1. Circuit design (1) The conducting polymer capacitor cannot be used in circuits that undergo frequent charging and discharging because the resulting internal heat buildup can cause capacitor failure. (2) Do not use the capacitor in time-constant or coupling circuits. In these type of circuit, electrical characteristics such as capacitance can change under certain environmental conditions. 2. Capacitor handling techniques (1) Capacitor insertion Incorrect land size may cause problems with capacitor placement and mountability. Refer to the land size table for appropriate design dimensions. (2) Soldering When using a soldering iron, set the tip temperature to no more than 300 C, and work in as short a time as possible under 10 seconds. While soldering, do not apply strong force to the capacitor. Reflow soldering The conducting polymer capacitor is designed specifically for reflow soldering. Maintain soldering conditions (pre-heating, reflow temperature, time) within the range indicated in the product specifications. If soldering time is lengthened or temperature is higher, the heat can damage the capacitor element and / or the molded case. Do not perform reflow soldering more than twice. (3) Circuit board cleaning Capacitors can withstand immersion in solvent at 60 C or under for up to 5 minutes.
    [Show full text]
  • Characterization of Tantalum Polymer Capacitors
    Characterization of Tantalum Polymer Capacitors NEPP Task 1.21.5, Phase 1, FY05 Erik K. Reed Jet Propulsion Laboratory Abstract Solid-electrolyte tantalum capacitors were first developed and commercially produced in the 1950s. They represented a quantum leap forward in miniaturization and reliability over existing wound-foil wet electrolytic capacitors. While the solid tantalum capacitor has dramatically improved electrical performance versus wet-electrolyte capacitors, especially at low temperatures, today’s electronic circuits require even better performance. In response to this need, steady improvements in the equivalent series resistance (ESR) of tantalum capacitors have been made. Low ESR is the most important attribute of capacitors used to filter and de- couple power for high-speed digital electronics. While the first patented tantalum capacitor was claimed to have ESR of roughly 2.0 ohms, a similar capacitor today has ESR of about 0.1 ohms. Even so, today’s digital electronics frequently require capacitors to have ESR in the low milliohms, a level that can be achieved with conventional tantalum capacitors only by connecting many in parallel. A substantial fraction of the ESR of a tantalum capacitor comes from its solid electrolyte material, manganese dioxide (MnO2). While MnO2 is substantially more conductive than almost all wet electrolytes, especially at low temperatures, capacitor manufacturers search for higher conductivity materials to replace MnO2. Today’s solid electrolyte material of choice is the conductive polymer PEDT (polyethylene- dioxythiophene) which has up to 100 times MnO2’s conductivity and has generally acceptable compatibility with tantalum pentoxide, the tantalum capacitor’s dielectric. With the introduction of conductive polymer electrolyte, remarkable improvements in capacitor ESR are possible.
    [Show full text]
  • Žižz. 44 43 U.S
    USOO7676921B2 (12) United States Patent (10) Patent No.: US 7,676,921 B2 Kim et al. (45) Date of Patent: Mar. 16, 2010 (54) METHOD OF MANUFACTURING PRINTED (56) References Cited CIRCUIT BOARD INCLUDING EMBEDDED CAPACTORS U.S. PATENT DOCUMENTS 5,010,641 A 4, 1991 Sisler (75) Inventors: Jin Cheol Kim, Gyeonggi-do (KR); Min 5,079,069 A 1/1992 Howard et al. Soo Kim, Kyunggi-do (KR); Jun Rok 6,005,197 A * 12/1999 Kola et al. .................. 174,260 Oh, Seoul (KR): Tae Kyoung Kim, 6,577,490 B2 * 6/2003 Ogawa et al. ............... 361,766 Gyeonggi-do (KR) 6,663,946 B2 12/2003 Seri et al. 6,764.931 B2 * 7/2004 Iijima et al. ................. 438,584 (73) Assignee: Samsung Electro-Mechanics Co., Ltd., 2004/O150966 A1 8, 2004 Hu Kyunggi-Do (KR) 2004/0231885 A1* 11/2004 Borland et al. ................ 29,846 (*) Notice: Subject to any disclaimer, the term of this FOREIGN PATENT DOCUMENTS patent is extended or adjusted under 35 JP 6-152137 5, 1994 U.S.C. 154(b) by 168 days. JP 2002-344146 11, 2002 JP 2003-5 1427 2, 2003 (21) Appl. No.: 11/670,463 * cited by examiner (22) Filed: Feb. 2, 2007 Primary Examiner Donghai D. Nguyen (65) Prior Publication Data (74) Attorney, Agent, or Firm Darby & Darby PC US 2007/O24O3O3 A1 Oct. 18, 2007 (57) ABSTRACT Related U.S. Application Data A method of manufacturing a printed circuit board including (62) Division of application No. 11/031,508, filed on Jan. 6, embedded capacitors, composed of a polymer condenser 2005, now Pat.
    [Show full text]
  • Conductive Polymer Capacitors Guidelines
    TECHNICAL PAPER Conductive Polymer Capacitors Basic Guidelines S. Zedníček, J.Petržílek, and P.Vanšura AVX Czech Republic s.r.o., Dvorakova 328, 563 01 Lanskroun, Czech Republic M.Weaver and C.Reynolds AVX Corporation One AVX Boulevard Fountain Inn, SC 29644-9039 USA Abstract: Conductive Polymer Capacitors are relatively new solid electrolytic capacitor technology on the market. The range of application is growing also due to their low ESR and safe operational characteristics. The paper addresses frequently asked questions about product life, construction, parametric performance, product specifications, recommendations and applications. 20202020©© A Basic Guide to AVX Conductive A: Compared to traditional (MnO2 electrolyte) tantalum Polymer Capacitors (Q&A) capacitors, they have: - Significantly lower ESR 1: Introduction to Polymer Capacitors (with associated higher ripple current ratings); - Improved Capacitance retention at high frequency The AVX solid electrolyte capacitor product range - Higher energy density (Joules/cc); provides an exceptional portfolio of technologies, - Wider voltage range including traditional manganese oxide electrolytic (with ratings available from 2.5v to 125v); capacitors (Tantalum/MnO2), the award winning - Less voltage derating required; ® Niobium Oxide (OxiCap ) series, and a wide range of - Benign failure mode if short-circuited. low ESR conductive polymer solid electrolytic capacitors, including market highest voltage ratings and also Q2: What are the key limitations of Conductive hermetically sealed high reliability polymers (award Polymer Capacitors? winner). A: Compared to traditional (MnO2 electrolyte) Tantalum Being based on similar electrochemistry and design capacitors, they typically have: principals, all these solid electrolytic technologies share the same basic electrical characteristics and behavior - Temperature range of -55oC to 105oC max.
    [Show full text]